FK037, a new parenteral cephalosporin with a broad antibacterial spectrum: synthesis and antibacterial activity.

Sir: In recent years, a number of new parenteral cephalosporins with a broad spectrum of antibacterial activity and a high stability against various /Mactamases have been reported1}. Most of them have a 7j5-[(Z)-2-(2-aminothiazol-4-yl)-2-alkoxyiminoacetamido] side chain, such as ceftizoxime (CZX) and ceftazidime (CAZ). They show excellent activity against Gram-negative bacteria and moderate activity against Gram-positive bacteria, especially Staphylococcus aureus. Recently, 3'-quaternary ammonium cephalosporins, such as cefpirome (CPR)2) and cefepime (CFPM)3) which show increased activity against both Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa have been developed. Thus, our efforts have been focused on synthesizing novel 3'-quaternary ammoniumcephalosporins with enhanced activity against Grampositive and Gram-negative bacteria including P. aeruginosa. As a result, we have discovered a new parenteral cephalosporin, FK037 (1), 7/?-[(Z)-2-(2aminothiazol-4-yl)-2-methoxyiminoacetamido] -3[3-amino-2-(2-hydroxyethyl)pyrazolio]methyl-3cephem-4-carboxylate sulfate. In this paper we report the synthesis and antibacterial activity of FK0374).